Portable containers for the transport of liquid fuel are commonly referred to as gasoline cans. Currently gasoline cans are generally made of blow molded plastic and have nozzles which are separable therefrom in which the nozzles can be positioned back within the gasoline can orifice during storage of the gasoline can. Recent developments in gasoline can technology provide means to prevent escape of VOCs into the atmosphere. In practice many trades people who use portable gasoline cans often leave them after use with their nozzles attached and facing upwards without capping them to prevent VOCs from being released into the atmosphere. The need to prevent of the escape of VOCs from gasoline cans is urgent, and many regulatory organizations such as the California Air Research Bureau have formulated specifications for gasoline cans to assure that they do not emit VOCs into the atmosphere. These regulations are being adopted by more and more states.
Current gasoline cans are derived from the old, metal “Jerry cans” that were used in WWII, but today's gasoline cans are composed of high-density polyethylene rather than of metal. Thus they are very rugged and impervious to the constituent elements of gasoline, kerosene and diesel fuel. Gasoline cans are available in different sizes, such as 2.5 gallon and 5 gallon cans. In recent years they have been color-coded to reflect their contents where a red can indicates that it contains gasoline; a yellow can, diesel fuel; and a blue can, kerosene.
Portable gasoline cans are used by home owners, for example, to fill lawn mowers; and such use accounts for a significant amount of VOC emissions escaping into the air. According to calculations from the U.S. Environmental Protection Agency, emissions from gasoline cans contribute approximately 22.4 tons of volatile organic compounds (VOCs) per day just in the Chicago metropolitan area. VOC emissions from gasoline cans can also occur due to evaporation and from fuel spillage; therefore it is desirable to have a gasoline can that includes shutoff means for preventing fuel evaporation and inadvertent spillage.
Such fuel dispensing cans must have an air vent to allow air to enter the can while the fuel is exiting the can so as to prevent a vacuum lockup which would prevent the fuel from easily exiting the gasoline can. Most prior art gasoline cans are somewhat rectangular or cylindrical in configuration and have an openable air vent usually disposed in the can wall generally opposite the positioning of the spout. The vent often has an openable and closeable cap that is often held on the vent by friction fit and, when opened, is retained to the vent by a tether. The vent is capped when closed to prevent the escape of VOCs. When one pours fuel from such gasoline can, one opens the vent to allow air to pass therethrough into the gasoline can to replace the volume of fluid as it exits the can through the spout.